Abstract: Examples of operating an Intelligent Electronic Device (IED) during power swings, are described. In an example, voltage measurements for a phase is received and sampled. Root mean square (RMS) values of the voltage samples is calculated based on the voltage measurements. Delta quantities for each phase are calculated based on the RMS values. Each of the RMS values and delta quantities are associated with respective sampling instants. In response to a delta quantity being greater than a predefined threshold, a peak delta quantity is detected. A time interval between a sampling instant associated with the peak delta quantity and a sampling instant associated with a first delta quantity is determined. Based on a comparison of the time interval with a threshold time, a disturbance condition may be detected as a power swing and consequently, fault detection at the IED may be blocked.

Abstract: A test arrangement for adjusting a setup of testing a device under test (DUT) includes a main device that generates an RF signal and processes an incoming RF signal in a first frequency range; a frontend component generates an RF signal and processes an incoming RF signal in a second frequency range. The frontend component measures a signal level in a sub-range within the first frequency range; a connection cable connects the main device with the frontend component; and an analyzer predicts a behavior of the connection cable in a rest portion of the first frequency range that is different from the sub-range within the first frequency range.

Abstract: The present invention relates to a low-thermal resistance pressing device for a socket, which mainly comprises a housing, an inner collar, a heat conductive pressing block, a bearing collar and a locking member. The locking member on the housing is used to lock the socket. The inner collar is threadedly engaged with the housing. The bearing collar is located between the inner collar and the heat conductive pressing block. In the case of rotating the inner collar in the housing, the bearing collar drives the heat conductive pressing block to move axially so as to exert an axial force to a device to be tested. Because the heat conductive pressing block protrudes from the upper and lower surfaces of the housing, one end thereof can be in contact with a temperature control module, and the other end thereof can be in contact with the device to be tested.

Abstract: A chip testing apparatus including a chip testing machine, a temperature testing device, and a lid is provided. The chip testing machine includes a substrate and a plurality of chip testing sockets. Each of the chip testing sockets is disposed on the substrate and configured to carry a chip under test. The temperature adjusting device is disposed on the chip testing machine, and the lid covers the temperature adjusting device and the chip testing sockets. The temperature adjusting device includes a main body and a plurality of pressing components. The main body includes a plurality of fluid channels, and each of the pressing components can press one side of one of the chips under test. A fluid can flow into one of the fluid channels and flow through the pressing components, so that the chips under test are in an environment having a predetermined temperature.

Abstract: The present disclosure provides a method and a system for testing semiconductor device. The method includes the following operations. A wafer having an IC formed thereon is provided. The IC is energized by raising the voltage of the IC to a first voltage level during a first period. A stress signal is applied to the IC. The stress signal includes a plurality of sequences during a second period subsequent to the first period. Each of the sequence has a ramp-up stage and a ramp-down stage. The stress signal causes the voltage of the IC to fluctuate between a second voltage level and a third voltage level. Whether the IC complies with a test criterion is determined after applying the stress signal.

Abstract: Systems, methods, and apparatuses are described for verifying the authenticity of an integrated circuit device. An integrated test apparatus may use quiescent current and/or conducted electromagnetic interference readings to determine if a device under test matches the characteristics of an authenticated device. Deviations from the characteristics of the authenticated device may be indicative of a counterfeit device.

Abstract: The disclosure describes a process and apparatus for accessing devices on a substrate. The substrate may include only full pin JTAG devices (504), only reduced pin JTAG devices (506), or a mixture of both full pin and reduced pin JTAG devices. The access is accomplished using a single interface (502) between the substrate (408) and a JTAG controller (404). The access interface may be a wired interface or a wireless interface and may be used for JTAG based device testing, debugging, programming, or other type of JTAG based operation.

Abstract: Techniques facilitating determination and correction of physical circuit event related errors of a hardware design are provided. A system can comprise a memory that stores computer executable components and a processor that executes computer executable components stored in the memory. The computer executable components can comprise a simulation component that injects a fault into a latch and a combination of logic of an emulated hardware design. The fault can be a biased fault injection that can mimic an error caused by a physical circuit event error vulnerability. The computer executable components can also comprise an observation component that determines one or more paths of the emulated hardware design that are vulnerable to physical circuit event related errors based on the biased fault injection.

Abstract: A chip testing apparatus and system suitable for performing testing on multiple chips in a chip cluster are provided. The chip testing apparatus includes a signal interface and a test design circuit. The signal interface transmits an input signal and multiple driving signals in parallel from a test equipment to each of the chips. The test design circuit receives multiple output signals from the chips through the signal interface and serially outputs a test data to the test equipment according to the output signals.

Abstract: The invention: determines if the duration of the conducting state of the semiconductors in a first cycle of the pulse width modulation is upper than a predetermined duration, measures, during the conducting state of the semiconductors at a second cycle, the voltage provided to the load, sequentially disables the conduction of each semiconductor during a part of the duration of the conducting state of the semiconductors in a third cycle and measures the voltage provided to the load, determines the differences between the voltage measured during the second cycle and each voltage measured during the third cycle, orders the differences according to their value, checks if the determined order is identical to an order stored in a memory of the device and determines that one connection of one semiconductor is deteriorated if the order is changed.

Abstract: A keyboard with wire aging self-adaption, a self-adaption method for keyboard, an electronic computing device readable medium with a stored program, and an electronic computing device program product are provided. In the keyboard, a processor feeds a scanning signal to each scanning line in turn during a scanning round. In response to the conduction state of one of switching elements, the processor detects a return signal on the corresponding return line and selects one or more scanning lines as a testing line. During a first duration in which the testing line maintains the scanning signal, according to the time difference between the starting points of the first duration and the return signal and the response time parameter corresponding to the testing line that is stored in the memory, the processor determines whether to update the response time parameter corresponding to the testing line that is stored in the memory.

Abstract: A battery monitoring apparatus includes an electric power supply terminal connected with a first electrical path, a voltage input terminal connected with a second electrical path, a signal control unit connected with a third electrical path, a response signal input terminal connected with a fourth electrical path, and a calculating unit. The signal control unit is configured to cause a predetermined AC signal to be outputted from a storage battery with the storage battery itself being an electric power source for the output of the predetermined AC signal. The calculating unit is configured to calculate, based on a response signal of the storage battery to the predetermined AC signal, a complex impedance of the storage battery. Moreover, at least one of the first to the fourth electrical paths is merged with at least one of the other electrical paths into an electrical path that is connected to the storage battery.

Abstract: A processor-implemented method of estimating a state of a battery includes acquiring current information and voltage information of a battery; determining time interval values based on the acquired current information such that current integration values corresponding to the time variation values satisfy a condition; determining voltage values corresponding to the determined time interval values in the acquired voltage information; and determining state information of the battery based on the determined voltage values.

Abstract: A system for testing a battery cell includes a test fixture configured to enclose the battery cell, a battery cycler configured to alternately charge and discharge the battery cell, an antenna mounted on a surface of the test fixture, the antenna configured to detect an electromagnetic signature of the battery cell and generate a signal indicative of the electromagnetic signature, and a detection module configured to receive the signal and detect characteristics of the battery cell based on the signal.

Abstract: The present invention relates to an apparatus and a method capable of calculating insulation resistances and parasitic capacitances of a battery outside the battery. In the present invention, when a positive electrode connector and a negative electrode connector are coupled to a positive electrode terminal and a negative electrode terminal of the battery, respectively, and a ground connector is coupled to a case of the battery, even though the battery is positioned inside a chamber in order to perform a temperature test or the like of the battery, the insulation resistances and the parasitic capacitances of the battery may be calculated without needing to move the battery to the outside of the chamber. Accordingly, the insulation resistances and the parasitic capacitances of the battery may be conveniently calculated.

Abstract: The battery residual value display device includes: a battery information receiving module; an attenuation function determining module; a second residual value determining module; a graph output module configured to output a graph of which one axis indicates residual values of a battery and another axis indicates information on an elapsed time from a time of manufacture of the battery; and a display unit. The graph output module is configured to output: in the graph, a display indicating a first residual value; a display indicating boundaries between a plurality of residual value ranks obtained by dividing the residual values in accordance with a level of a second residual value; and a display indicating boundaries between a plurality of groups, indicating types of applications in which the battery can be used, obtained by dividing the plurality of residual value ranks in accordance with the level of the second residual value.

Abstract: A power supply monitor includes a delta-sigma modulator including an input receiving a binary number and an output providing a pulse-density modulated signal, the delta-sigma modulator operable to scale the pulse-density modulated signal based on the binary number. A fast droop detector circuit includes a level shifter providing the modulated signal referenced to a clean supply voltage. A lowpass filter is coupled between the level shifter and a comparator. The comparator produces a droop detection signal at said output responsive to a monitored supply voltage dropping below a predetermined level relative to the filtered signal.

Abstract: Connection normality check of a pair of electric wires is simplified. A circuit check device 1 that checks connection normality of a pair of electric wires L1 and L2 includes, when the pair of electric wires is connected to an exchange 2, a voltmeter 11 that measures a first inter-wire potential difference between one end of an electric wire portion p1 of the electric wire L1 and one end of an electric wire portion p2 of the electric wire L2, a voltmeter 12 that measures a second inter-wire potential difference between the other end of the electric wire portion p1 of the electric wire L1 and the other end of the electric wire portion p2 of the electric wire L2, and a determiner 13 that determines whether the measured first inter-wire potential difference agrees with the measured second inter-wire potential difference.

Abstract: A multi-core cable testing device is configured to specify a correspondence between ends of an insulated wire at both ends of a multi-core cable including insulated wires. The device includes a signal input unit for inputting a test signal by capacitive coupling into one end of the insulated wire as a testing object at one end of the multi-core cable, a signal output unit for outputting the test signal by capacitive coupling from each end of the insulated wires at the other end of the multicore cable, a correspondence specifying unit for measuring a voltage of the test signal from the signal output unit and for specifying an other side end of the insulated wire based on a measured voltage. At least one of the signal input unit and the signal output unit includes a signal transmission cable for transmitting the test signal and a substrate configured to be connected to the signal transmission cable.

Abstract: Provided are a reliable high-voltage system and a failure diagnosis method thereof, in which a vibration damping mechanism using an electrorheological fluid as a working fluid is a load, and can prevent electric shock due to leakage current and the influence on surrounding electronic devices. There are provided a first circuit that includes a power source and a ground, a second circuit that is magnetically coupled to the first circuit via a transformer and includes a load connected to the ground, a controller that is connected to the ground, a third circuit that is connected to the second circuit and the ground, a first resistor that is provided between a connection point at a high potential end of the second circuit and the ground, and a second resistor that is provided between a connection point at a low potential end of the second circuit and the ground, and has a resistance value different from a resistance value of the first resistor.

Abstract: This sensor unit includes a base having a substantially-rectangular planar shape including a first side and a second side that are substantially orthogonal to each other, and a plurality of first sensors provided on the base and arranged on a first axis. The first axis is substantially parallel to the first side and passes through a center position of the base.

Abstract: A receiver for detecting at least one electromagnetic signal while the receiver is moving relative to the Earth's magnetic field, the receiver comprising: an SQUID array for generating an output that is a transfer function of SQUID array magnetic flux that is supplied from a combination of an oscillating magnetic field of the at least one electromagnetic signal, the Earth's magnetic field, and a bias magnetic field; a bias-tee configured to divide the SQUID array output into a DC signal and an RF signal; a memory store configured to store a plurality of voltage and flux bias values, wherein each voltage value has a corresponding flux bias value that results in maximum SQUID array sensitivity; and a logic circuit configured to find a voltage value in the memory store that most closely matches the DC signal, and to apply to the SQUID array a flux bias corresponding to the most closely matched voltage value.

Abstract: A position sensing system has a trim unit to trim hall voltages generated by a first sensor and a second sensor in response to an excitation current, to compensate a non-orthogonality of the first sensor and the second sensor.

Abstract: In one aspect, a linear sensor includes at least one magnetoresistance element that includes a first spin valve and a second spin valve positioned on the first spin valve. The first spin valve includes a first set of reference layers having a magnetization direction in a first direction and a first set of free layers having a magnetization direction in a second direction orthogonal to the first direction. The second spin valve includes a second set of reference layers having a magnetization direction in the first direction and a second set of free layers having a magnetization direction in a third direction orthogonal to the first direction and antiparallel to the second direction. The first direction is neither parallel nor antiparallel to a direction of an expected magnetic field.

Abstract: In one aspect, a method includes forming a metal layer on a substrate, wherein the metal layer comprises a first coil, forming a planarized insulator layer on the metal layer, forming at least one via in the planarized insulator layer, depositing a magnetoresistance (MR) element on the planarized insulator layer, and forming a second coil extending above the MR element. The at least one via electrically connects to the metal layer on one end and to MR element on the other end.

Abstract: An Optically Pumped Magnetometer (OPM) system is configured to characterize a magnetic field. The OPM system comprises an OPM sensor that is coupled to an OPM cable that is coupled to an OPM connector that is detachably coupled to an OPM controller. The OPM connector stores OPM operational data. The OPM controller reads the OPM operational data when the OPM connector is coupled to an OPM controller. The OPM controller generates sensor control signals based on the OPM operational data and transfers the control signals to the OPM sensor. The OPM sensors characterize the magnetic field in response to the sensor control signals and transfer output signals that characterize the magnetic field to the OPM controller. The OPM controller models the magnetic field based on the output signals and transfers new OPM operational data to OPM connector. The OPM connector stores the new OPM operational data in the memory.

Abstract: A method is for automatic interaction with a patient during a magnetic resonance examination with a magnetic resonance apparatus. In an embodiment, the method includes detecting an acoustic utterance of the patient; processing the acoustic utterance of the patient via a speech processor, the processing of the acoustic utterance including at least determining the communication as a function of the acoustic utterance and checking the communication for a correlation with a parameter of the magnetic resonance examination; determining the output as a function of the communication of the patient and the parameter of the magnetic resonance examination and providing the output. A magnetic resonance apparatus of an embodiment includes at least a processor to carry out an embodiment of the method. The method can further be stored on a computer program product or medium for execution by a processor.

Abstract: An NMR magnet system uses a Stirling cooler having a cold head that extends into a housing of the system to cool a cold shield surrounding a cryogen vessel. The system may have a damper located between the cooler and the cold shield to reduce a transmission of vibration from the cooler to a magnet coil immersed in the cryogen. The damper may be passive, or may be part of an active damping system that uses an acceleration sensor to drive an active damper that compensates for cooler vibration. A compensation apparatus may use a stored characteristic of a signal distortion caused by the vibration and, in response to a trigger signal from the cooler, apply compensation to an excitation signal provided to a sample by an NMR probe in a bore of the magnet coil, or to an FID signal from the sample that is detected by the probe.

Abstract: Various methods and systems are provided for radio frequency coil units for magnetic resonance imaging. In one example, a radio frequency (RF) coil unit for magnetic resonance imaging (MM) includes an outer layer forming an exterior of the RF coil unit, a pressure reservoir enclosed by the outer layer, wherein the pressure reservoir forms a sealed chamber, and an array of RF coil elements enclosed by the outer layer, wherein the array of RF coil elements is disposed outside of the sealed chamber of the pressure reservoir.

Abstract: A magnet suitable for use in a Magnetic Resonance Imaging (MRI) system. The magnet includes a magnet body having a bore extending therethrough along an axis of the body and a primary coil structure having at least four primary coils positioned along the axis. A first end coil is adjacent a first end of the bore of the magnet and a second end coil is adjacent a second end of the magnet. The first end coil and the second end coil are spaced apart by no more than 1000 mm and an imaging region produced by the primary coils is of a disk-type.

Abstract: A method for measuring a gradient field of a nuclear magnetic resonance (NMR) system based on a diffusion effect uses a non-uniform field magnet, an NMR spectrometer, a radio frequency (RF) power amplifier, an RF coil, and a standard quantitative phantom with known apparent diffusion coefficient (ADC) and time constant for decay of transverse magnetization after RF-pulse (T2). A plurality of sets of signals are acquired by an NMR sequence with different diffusion-sensitive gradient durations or different echo spacings and the magnitude of the gradient field is calculated by fitting based on the plurality of sets of signals. The method does not require an additional dedicated magnetic field detection device, has a short measurement time, is easy to use with the NMR system, and is convenient to complete gradient field measurement at the installation site, thereby improving the installation and service efficiency of the NMR system.

Abstract: A system and method is provided for controlling physiological-noise in functional magnetic resonance imaging using raw k-space data to extract physiological noise effects. The method can identify these effects when they are separable and directly reflects the artefactual effects on fMRI data, without the need for external monitoring or recording devices and to be compensated for via rigorous statistical analysis modeling of such noise sources. The physiological fluctuations may be treated as global perturbations presented around the origin point in a k-space 2D slice. Each k-space 2D slice may be acquired at a very short repetition time with an effective sampling rate to sample cardiac and respiratory rhythms through proper reordering and phase-unwarping techniques applied to the raw k-space data.

Abstract: Systems and Methods that identify the effect of motion during a medical imaging procedure. A neural network is trained to translate motion induced deviations of a coil-mixing matrix relative to a reference acquisition into a motion score. This score can be used for the prospective detection of the most corrupted echo trains for removal or triggering a replacement by reacquisition.

Abstract: A heliostat calibration system having a system controller, and a heliostat having a heliostat controller, wherein: the system controller is configured to receive a calibration data point and initial calibration offset angle guess, calculate a tracking error, identify a calibration offset angle, and the heliostat controller configured to transmit a calibration data point, receive adjustment instructions, and execute the adjustment instructions.

Abstract: A technique for polar aligning the mount of a telescope or other astronomical instrument includes acquiring star images from an electronic polar scope and determining a location of a celestial pole relative to the star images based on computerized matching of the star images to information in a database. The mount has a right-ascension (RA) axis, and the technique directs an adjustment to the mount so as to align a location of the RA axis with the determined location of the celestial pole.

Abstract: The positioning capabilities of a User Equipment (UE) are stored in a core network to reduce positioning latency when the UE indicates that its positioning capabilities are stable and/or are long term valid. The UE may provide its positioning capabilities to a location server during a location session along with an indication of whether the positioning capabilities are stable. The location server may enable storage of the positioning capabilities for the UE in the core network, e.g., in the location server or another entity in the core network such as Access and Mobility Management Function (AMF), if there is an indication that the positioning capabilities are stable. The AMF may include a UE identifier in location requests with which the location server may retrieve the UE positioning capabilities if stored at the location server or may include the UE positioning capabilities if stored at the AMF.

Abstract: A system and method for a second wireless device to establish distance and location of a first device which is transmitting radio waves includes the first and second devices. Each second device includes two or more (N in number) receiving antennas. An angle between the directions in which adjacent receiving antennas receive the strongest signals is 360°/N. The second device obtains a received signal strength indicator (RSSI) of each receiving antenna receiving signals from the first device, and from the two strongest receiving antennas, calculation of an angle between the first device and one of the adjacent receiving antennas can be performed. The distance between the first device and the second device can also be calculated.

Abstract: A method for interference reduction between radar units. The method is performed by a radar unit and comprises: receiving one or more radar frames, wherein the one or more radar frames correspond to one or more respective time intervals during which the radar unit was activated to transmit and receive signals to produce data samples of the one or more radar frames; and determining whether the one or more radar frames have a higher presence of data samples that are subject to interference from other radar units in a first half of their corresponding time intervals than in a second, later, half of their corresponding time intervals. In case the presence is higher in the first half of their corresponding time intervals, a scheduled time interval of an upcoming radar frame to be produced by the radar unit is postponed, and otherwise it is advanced.

Abstract: Antenna array systems and methods for simulating QPSK beam forming having binary phase shifter associated with each transmitting antenna configured to apply a phase shift of 180 degrees to a transmitted signal, and a controller configured to send instructions to the binary phase shifters. The receiving antennas are connected to a post processor comprising a memory operable to save received signals; and a processing unit operable to apply a 90 degree phase shift to selected received signals stored in the memory, and further operable to sum received signals stored in the memory. Optimized antenna array configurations are disclosed.

Abstract: A method for calibrating a cascaded radar system includes transmitting first radar transmission signal from a radar device. First radar reflection signals corresponding to the respective first radar transmission signal reflected from calibration target are received at each of the radar devices. The first radar reflection signals are demodulated to generate first baseband signals at each of the radar devices. A second radar transmission signal is modulated with respect to the first radar transmission signal at the respective one of the radar devices. The second radar transmission signal is transmitted from the respective one of the radar devices and are received as second radar reflection signals at each of the radar devices. The second radar reflection signals are demodulated to generate second baseband signals at each of the radar devices, and each of the radar devices are calibrated based on the first and second baseband signals.

Abstract: A target device, which allows a sufficient amount of reflected light to be obtained from an end portion, is provided and includes a measurement section. In the target device, a retroreflective layer in which a plurality of retroreflective elements are arranged on the entire circumference in a circumferential direction about an axis is formed on at least part of the outer peripheral surface of the measurement section. The retroreflective layer is formed into an uneven shape in which a distance from the axis changes along the entire circumference in the circumferential direction.

Abstract: An enclosure for an optoelectronic sensor. The enclosure includes a thermodynamically open first chamber; a thermodynamically closed second chamber; and a rotor extending from the first chamber into the second chamber. The rotor includes a shaft part in the second chamber coaxial to the rotational axis of the rotor. The shaft part mounts an optoelectronic sensor device. The rotor includes a head part in the first chamber coaxial to the rotational axis of the rotor. A heat dissipation fan is fixedly arranged on and surrounds the head part. The head part and the fan are rotatably and thermally coupled to the shaft part to rotate simultaneously with the shaft part. The rotor transfers heat over the shaft part from the second chamber to the head part and the fan dissipates the transferred heat to an environment.

Abstract: A lidar system that includes a laser source and transmits laser pulses produced by the laser source toward range points in a field of view via a mirror that scans through a plurality of scan angles can use (1) a laser energy model to model the available energy in the laser source over time and (2) a mirror motion model to model motion of the mirror over time. A shot list for the upcoming laser pulse shots that are modeled according to the laser energy and mirror motion models can further be controlled based on eye safety and/or camera safety models to prevent the lidar system firing too much laser energy into defined spatial areas over defined time periods and thus reduce the risk of damage to eyes and/or cameras in the field of view.

Abstract: Various examples for multi-tone continuous wave detection and ranging are disclosed herein. In some embodiments, an initial signal is generated using initial radio frequency (RF) tones, and is emitted as a multi-tone continuous wave signal. The initial signal is reflected from a target and received as a reflected signal. Resultant RF tones, including a frequency and a power, are determined from the reflected signal in a frequency domain. A frequency-domain sinusoidal wave is fitted to the resultant RF tones in the frequency domain, and a distance to the target is determined using a modulation of the frequency-domain sinusoidal wave.

Abstract: An electronic device comprising circuitry configured to sample, in a calibration phase using a known time-of-flight ?D, a first set of differential mode measurements ?cal (n??E,?D) according to a first sampling strategy tEcal, and to determine Fourier coefficients Mk of the first set of differential mode measurements ?cal(?E,n,?D) based on the known time-of-flight (?D) used in the calibration phase, and to determine a cyclic error (fCE(?1,?(?D);x)) based on the Fourier coefficients (Mk).

Abstract: Various aspects of the subject technology relate to a mobile support platform for vehicle sensor calibration. The mobile support platform includes a chassis, lift posts on the chassis configured to interface with one or more lift points on a vehicle and raise the vehicle, and a set of wheels mounted to the chassis configured to carry the vehicle through a calibration sequence.

Abstract: An ultrasound imaging system includes a thermally conductive frame and a number of electronic components and a display that are sealed within the frame. The frame further includes a plenum extending through the frame with surfaces that are thermally coupled to the electronic components and the display. An active cooling mechanism, such as one or more fans, moves air through the plenum to remove heat generated by the electronic components and display. The plenum is environmentally sealed so that moisture, dust, air or other contaminants drawn into the plenum do not contact the sealed electronic components and display in the frame.

Abstract: An ultrasound probe contains an array transducer and a microbeamformer coupled to elements of the array. The microbeamformer comprises one or more analog ASICs containing transmitters and amplifiers coupled to transducer elements, and one or more digital ASICs containing analog to digital converters and digital beamforming circuitry. The analog ASICs and the digital ASICs are manufactured by different integrated circuit 5 processes, with that of the analog ASIC optimized for high voltage analog operation and that of the digital ASICs optimized for high density, low voltage digital circuitry.

Abstract: A position determination system a determines whether a mobile terminal is present outside a vehicle compartment based on a reception strength of a radio signal transmitted from the mobile terminal through a vehicle interior antenna and a reception strength of a radio signal transmitted from the mobile terminal through a vehicle exterior antenna, and the vehicle exterior antenna is configured to be disposed in a predetermined region in a vicinity of a window of a vehicle in an outer surface portion of a vehicle.

Abstract: An estimation method is provided which includes: calculating a plurality of complex transfer functions, based on reception signals respectively received by N reception antenna elements during a predetermined period, the complex transfer functions each representing propagation characteristics between a transmission antenna element and the N reception antenna elements; extracting a variation component corresponding to each of the N reception antenna elements, from the calculated complex transfer functions, the variation component being caused by a living body; calculating a correlation matrix based on the variation component corresponding to each of the N reception antenna elements; calculating eigenvalues of the correlation matrix calculated in the calculating of the correlation matrix; and estimating the number of living bodies in a predetermined method, using the eigenvalues calculated in the calculating of the eigenvalues.